Mazdaspeed 3 13.872@101.33

[erod550]

just a thought, chris my buddy with I/dp/noexhaust 91 pump gas and AP picked up over 70ftlbs of torque at revos dyno thanks to a protune at 17psi, over the stage2 93map. and if they take a bit more time, they can tune the k04 for 23psi at this altitude. thats what hes running now with partial e-85. should be good for mid-high 12's at bandi.

Tune the K04 to 23psi and you'll be replacing the turbo in no time. It's already out of its efficiency range at 18psi.

[Dange]

Tune the K04 to 23psi and you'll be replacing the turbo in no time. It's already out of its efficiency range at 18psi.

yeah thats his plan, hes getting deployed and is gonna rebuild and turboswap when he gets back

[dsm_luck]

just a thought, chris my buddy with I/dp/noexhaust 91 pump gas and AP picked up over 70ftlbs of torque at revos dyno thanks to a protune at 17psi, over the stage2 93map. and if they take a bit more time, they can tune the k04 for 23psi at this altitude. thats what hes running now with partial e-85. should be good for mid-high 12's at bandi.

Interesting but I have a question. Was he running just a straight OTS map from Cobb? If so the majority of his hp/tq gain could have been from the way the mazda ECU acts at altitude. Even on the Stage 2+ maps the boost would max out at 13 to 14 psi. I had to adjust the load and WGDC caps to get it to boost 18psi. That extra 4 to 5psi could account for 30 or 40 hp of the total gain.

Also why do they believe it is safe to run 23psi on the stock K04? At this altitude that would be equivalent to running 27-28psi. I cannot imagine that working or producing power. On my tune the stock turbo physically cannot push more than 14 psi from 5500 to redline. It starts at 18 psi and after 4.5k starts to slide down to 14psi @ 6500.

Not saying that he is not running 23psi but I would like to know how he did this safely? What was his uncorrected dyno? When is he going to track it? Slicks?

[dsm_luck]

i guess tires is the issue though lol

I hate how our cars will run that at sea level in stock trim. Stupid altitude.

Stock they don't trap that high though. You are right about second gear I need to be more patient and not just hammer the throttle. Methanol is going back on next week and then I am going to make some adjustments to the tune for the E85 mixture and maybe up the boost in the low to mid range and see if I can't crack mid 13's.

Anyone have a set of Slicks with rims that will fit the mazdaspeed? lol

[roninsoldier83]

Interesting but I have a question. Was he running just a straight OTS map from Cobb? If so the majority of his hp/tq gain could have been from the way the mazda ECU acts at altitude. Even on the Stage 2+ maps the boost would max out at 13 to 14 psi. I had to adjust the load and WGDC caps to get it to boost 18psi. That extra 4 to 5psi could account for 30 or 40 hp of the total gain.

Also why do they believe it is safe to run 23psi on the stock K04? At this altitude that would be equivalent to running 27-28psi. I cannot imagine that working or producing power. On my tune the stock turbo physically cannot push more than 14 psi from 5500 to redline. It starts at 18 psi and after 4.5k starts to slide down to 14psi @ 6500.

Not saying that he is not running 23psi but I would like to know how he did this safely? What was his uncorrected dyno? When is he going to track it? Slicks?

Typically on turbo cars I've played with in the past, when the hotside is no longer able to sustain a certain pressure at higher RPM's regardless of WGDC's, there is still torque under the curve/in the mid-range to be made.

Whenever I would play with a car, the boost would almost always be limited by one of 4 things:

-Knock/detonation.
-Torque curve does not improve with the addition of more boost.
-Lack of consistency.
-Lack of fuel overhead (max IDC's are at tuner's discretion).

IMO, running XX psi isn't necessarily "unsafe" most of the time, especially if it is tapering pretty hard up top (in-cylinder temps increase fairly linearly as RPM rises, so not holding as much pressure up top helps alleviate some stress on the motor). Although, if someone is dyno tuning a car, and with a conservative AFR & timing map are able to hit XX psi (23 in this case), and the area under the curve continues to increase, there is no knock present, plenty of fuel overhead and it's fairly repeatable (not losing 10-15+whp during back to back pulls), there's no reason it's not "safe" per se IMO.

Sure, the center cartridge is going to need to be rebuilt a bit sooner on the snail, but there's not necessarily a set "cap" on most turbos. Sure, the harder you push it, the further you're going to put the compressor out of it's efficiency range, resulting in higher IAT's, and a sharper torque curve (i.e. going to drop hard/look like a mountain peak), but that doesn't mean it's not "safe" for the motor. As you continue to increase boost, due to higher IAT's, your gains will be diminished, and typically when a compression stops adding peak power when increasing boost (due to inability to maintain close to peak pressure), I would pretty much stop upping the boost.

I'm only pointing this out as I remember back in the "early" Subaru days when people swore that anything over "17psi" or so was "way too high" on a VF-series and "unsafe"... whereas today, the fastest stock turbo STI's have been pushing 27+psi out of puny 35 lb/min compressors (VF39/43's), some for years on end without issue.

My whole point is: let your datalogs & torque curve determine your peak boost pressure, not some random information on the Internet. To include myself lol, no need to take my word for anything, experiment (at your own risk of course) for yourself.

With that said, 23psi on pump gas (91 octane I'm assuming) out of a K04 at this altitude does seem like a recipe for very high IAT's and knock unless you're running VERY little timing advance and wicked rich AFR's (which will diminish some of your gains made by pushing more boost...), but until we've seen the logs & torque curves, who's to say right? LOL.

Just my $.02

[dsm_luck]

Typically on turbo cars I've played with in the past, when the hotside is no longer able to sustain a certain pressure at higher RPM's regardless of WGDC's, there is still torque under the curve/in the mid-range to be made.

Whenever I would play with a car, the boost would almost always be limited by one of 4 things:

-Knock/detonation.
-Torque curve does not improve with the addition of more boost.
-Lack of consistency.
-Lack of fuel overhead (max IDC's are at tuner's discretion).

IMO, running XX psi isn't necessarily "unsafe" most of the time, especially if it is tapering pretty hard up top (in-cylinder temps increase fairly linearly as RPM rises, so not holding as much pressure up top helps alleviate some stress on the motor). Although, if someone is dyno tuning a car, and with a conservative AFR & timing map are able to hit XX psi (23 in this case), and the area under the curve continues to increase, there is no knock present, plenty of fuel overhead and it's fairly repeatable (not losing 10-15+whp during back to back pulls), there's no reason it's not "safe" per se IMO.

Sure, the center cartridge is going to need to be rebuilt a bit sooner on the snail, but there's not necessarily a set "cap" on most turbos. Sure, the harder you push it, the further you're going to put the compressor out of it's efficiency range, resulting in higher IAT's, and a sharper torque curve (i.e. going to drop hard/look like a mountain peak), but that doesn't mean it's not "safe" for the motor. As you continue to increase boost, due to higher IAT's, your gains will be diminished, and typically when a compression stops adding peak power when increasing boost (due to inability to maintain close to peak pressure), I would pretty much stop upping the boost.

I'm only pointing this out as I remember back in the "early" Subaru days when people swore that anything over "17psi" or so was "way too high" on a VF-series and "unsafe"... whereas today, the fastest stock turbo STI's have been pushing 27+psi out of puny 35 lb/min compressors (VF39/43's), some for years on end without issue.

My whole point is: let your datalogs & torque curve determine your peak boost pressure, not some random information on the Internet. To include myself lol, no need to take my word for anything, experiment (at your own risk of course) for yourself.

With that said, 23psi on pump gas (91 octane I'm assuming) out of a K04 at this altitude does seem like a recipe for very high IAT's and knock unless you're running VERY little timing advance and wicked rich AFR's (which will diminish some of your gains made by pushing more boost...), but until we've seen the logs & torque curves, who's to say right? LOL.

Just my $.02

Very interesting. Thank you for the post.

I usually am spraying meth in a 50/50 mixture as well. I assume this would help negate the higher boosted air temperature and keep it from knocking at higher boost levels.

Thing is my car never knocks outside of some off throttle weirdness every now and again. I monitor knock every time I drive. Do you think the driveability would be too extreme if I tried pushing 20psi on the low to mid end and kept the top end taper?

If I continue to get no knock then I assume the next step would be to check FP and also make sure my boosted air temps are not getting too high?

[erod550]

I had a protune and it would spike 19-20psi on the low end and taper to 17-18 by 5k and continue to taper until redline. Shouldn't drive any different that it does now if you push it to 20psi, just more power (and more heat). If you're wanting to keep the K04 long term though it's up for debate how quickly that will reduce the life of the turbo. Just ask Eric (OCD).

[chickenwafer]

FYI this is a K04 at 18psi with our corrected pressure ratio, plotted in red:



More boost does not always mean more power.

[dsm_luck]

FYI this is a K04 at 18psi with our corrected pressure ratio, plotted in red:

More boost does not always mean more power.

Can you explain to me how to read a compression map? I want to understand. Thanks.

[erod550]

http://www.coloradomazdaclub.com/forums/showthread.php?t=6772

[dsm_luck]

http://www.coloradomazdaclub.com/forums/showthread.php?t=6772

Thank you! Gives me something to read. This is exactly what i wanted to find. Before it feels like taking a stab in the dark with the K04 at this altitude and its efficiency.

[chickenwafer]

If you have any questions just ask or post them up in that thread

[roninsoldier83]

Very interesting. Thank you for the post.

I usually am spraying meth in a 50/50 mixture as well. I assume this would help negate the higher boosted air temperature and keep it from knocking at higher boost levels.

Thing is my car never knocks outside of some off throttle weirdness every now and again. I monitor knock every time I drive. Do you think the driveability would be too extreme if I tried pushing 20psi on the low to mid end and kept the top end taper?

If I continue to get no knock then I assume the next step would be to check FP and also make sure my boosted air temps are not getting too high?

You are correct, spraying meth/water typically has a fairly drastic cooling effect on your IAT's, although my 335xi is SD (Map based fueling), so our BAT's are typically simply logged as IAT's, whereas on the 2.3 DISI cars, I believe there are temp sensors in both the MAF & MAP sensor, so you should be able to log post turbo IAT's (referred to as BAT's), so to check the reduction in BAT's, simply make a couple pulls w/o meth, log BAT's, let the FMIC cool down, then make a couple pulls w/meth, and assuming you're injecting meth right before the throttle body, you should see a reduction.

Typically, if you up the peak boost on a small compressor/turbine like the K04, it's not going to hold anywhere close to peak boost at redline/will taper naturally. The driveability is going to be subjective... while some people prefer a more linear torque curve (typically what manufacturers shoot for), others prefer the kick-in-the-pants mid-range of a turbo that is pushing a lot of boost in the mid-range. Back in the day, my old STI was pushing around 21-22psi peak (pushing anymore boost than that didn't result in any power gain, so that's where I capped it) tapering to 12-13psi at redline, and while the torque curve had a sharp drop off, I did like the extra mid-range on the street.

If there's a way to check your calculated IDC's (not as easy as it is on a port injection motor), that's a good idea, although if you start running out of fuel at a certain spot in your curve, it will be obvious as the car will run lean. Typically, back in the day, depending on how reliable I considered the fuel system, and if the owner did a lot of traveling, I wouldn't recommend IDC's hit over 85-90%, even lower if they made frequent trips to sea level.

FYI this is a K04 at 18psi with our corrected pressure ratio, plotted in red:

More boost does not always mean more power.

I would definitely agree with that statement, which is why it's nice to be able to tune a car on a dyno, so you can actually overlay changes in the curve, and if upping the boost ceases to add power, at that point, I would cap the boost. On a MAF based car, if I was road tuning, I would typically just log & compare G/S, but prefer a dyno for that exact reason.

[dsm_luck]

You are correct, spraying meth/water typically has a fairly drastic cooling effect on your IAT's, although my 335xi is SD (Map based fueling), so our BAT's are typically simply logged as IAT's, whereas on the 2.3 DISI cars, I believe there are temp sensors in both the MAF & MAP sensor, so you should be able to log post turbo IAT's (referred to as BAT's), so to check the reduction in BAT's, simply make a couple pulls w/o meth, log BAT's, let the FMIC cool down, then make a couple pulls w/meth, and assuming you're injecting meth right before the throttle body, you should see a reduction.

Typically, if you up the peak boost on a small compressor/turbine like the K04, it's not going to hold anywhere close to peak boost at redline/will taper naturally. The driveability is going to be subjective... while some people prefer a more linear torque curve (typically what manufacturers shoot for), others prefer the kick-in-the-pants mid-range of a turbo that is pushing a lot of boost in the mid-range. Back in the day, my old STI was pushing around 21-22psi peak (pushing anymore boost than that didn't result in any power gain, so that's where I capped it) tapering to 12-13psi at redline, and while the torque curve had a sharp drop off, I did like the extra mid-range on the street.

If there's a way to check your calculated IDC's (not as easy as it is on a port injection motor), that's a good idea, although if you start running out of fuel at a certain spot in your curve, it will be obvious as the car will run lean. Typically, back in the day, depending on how reliable I considered the fuel system, and if the owner did a lot of traveling, I wouldn't recommend IDC's hit over 85-90%, even lower if they made frequent trips to sea level.




I would definitely agree with that statement, which is why it's nice to be able to tune a car on a dyno, so you can actually overlay changes in the curve, and if upping the boost ceases to add power, at that point, I would cap the boost. On a MAF based car, if I was road tuning, I would typically just log & compare G/S, but prefer a dyno for that exact reason.

The BATs drop significantly while spraying meth. I had it on a 10psi trigger and you could see them shoot down 20 or so degrees once the meth started flowing and would hold like that through the pull.

On the Mazdaspeeds the HPFP is the weak link on the fuels system. It usually is over 1550 psi at WOT but during the winter I did see a few 1200 psi at WOT pulls in very cold weather. I think after the methanol I need to get FP internals. The car usually runs 11.8 to 12.0 afr on a mix of E85 with no knock.

I guess I could get it dyno tuned but I like the idea of tinkering with it myself and im not secure enough in my tuning ability to do it myself on limited dyno time. For G/S are you referring to air flow at the MAF?

Cant you also use your IAT vs BAT to calculate how efficient your intercooling system is? People always talk about ambient temp but isn't the true measure of your system how well it controls heat from the time it hits the intake to the time is goes through the throttle body? The reason I ask is because my IATs is always higher than ambient unfortunately.

[erod550]

Your IATs are just the temp at the MAF so even with a cold air intake in perfect conditions your IATs won't be below ambient. With my Cobb SRI, I would see IATs around 7-8 degrees above ambient when driving down the road. BATs varied with how long I'd been driving, how warm it was outside, and at what speed I was driving. Like I said, at Bandi on my best 14.4 run, my BATs were getting up into the 180s. On a cold night on the highway I stayed right with a modded 6.0 GTO from a 60 roll until he started to pull on me at 120+. My BATs that night were in the 20s. Best the car ever ran. I was going to install meth this summer to help combat the high BATs but ended up trading it in.

But you're right, in the end, IATs aren't really all that important for you, since the air temperature changes after going through the turbo and intercooler. It's the BATs that are important, which are post intercooler.